The overall study goal is to understand how the elderly utilize risk information on Over-the-Counter (OTC) package labels to form their overall risk perceptions of using an OTC drug product, and to determine their sources of drug information. This study also examines the effects of the absence and presence of risk labeling information on older adults' OTC decisions. Specifically, study objectives are: (1) to propose a consumer's perceived risk model in evaluating OTC risk labeling information for the use of an OTC product in a particular situation; and (2) to test the model on consumers' overall risk perceptions and information sources. Adapting from the Bettman (1973), and Dowling and Staelin (1994) frameworks in marketing research, perceived risk is proposed to consist of 3 risk components: (a) Product Category Risk (PCR) defined as risk associated with a product class; (b) Product Specific Risk (PSR) defined as risk associated with a specific product's characteristics; and (c) Situation Specific Risk (SSR) defined as risk associated with the user's characteristics. This study will employ a completely randomized controlled 2 x 2 x 2 x 2 factorial design to test the effects of the proposed perceived risk model. There will be 16 treatment groups and 2 control groups. Each treatment is operationalized with the following levels of risk: (1) PCR (low risk = cold products vs. high risk = pain relievers); (2) PSR (low risk = 2 side effects vs. high risk = 4 side effects); (3) SSR (low risk = dry skin vs. high risk = diabetes); and (4) presence of SSR information on label (yes vs. no). There are two dependent variables of interest: (1) overall perceived risk of using the OTC product operationalized as consisting of two dimensions: uncertainty and adverse consequences; and (2) information sources operationalized as the likelihood of searching for additional information beyond the label, and the likelihood of using, trusting, and preferring particular sources of information. A sample of 1,620 subjects will be randomly selected from a national commercial consumer mailing list of U.S. adults aged 65 years and older. An initial pilot study will be conducted in a sample of 612 subjects to test the instrument. Each subject will be randomized to a treatment or control group, and mailed one of the 18 versions of a survey packet depending on their assigned group. Each survey packet will contain a cover letter, a 7-page questionnaire and a prepaid return envelope. Subjects are asked to answer questions on their risk perceptions of using a hypothetical OTC product and the sources they would use for drug information after reading a product label and a health scenario for which the product is to be used. The study is relevant to better understanding how elderly consumers make use of OTC risk labeling information in their OTC decisions in order to improve the quality and safety of OTC medication use by the older adults. Study implications include improving OTC package labeling and developing strategies to correct public misconceptions of OTCs. Furthermore, knowledge of the elderly population's choice of OTC drug information sources would be of help to health care professionals engaged in OTC counseling in better handling of patients' questions and concerns. [unreadable] [unreadable] [unreadable]